#include<iostream>
#include<string>
#include<cstdlib>
#include<cmath>

class complex{
    double real;
    double virt;
    public:
        complex(){
            complex(0,0);
        }
        complex(double r,double v){
            real=r;
            virt=v;
        }
        complex operator+(complex c){
            return {real+c.real,virt+c.virt};
        }
        complex operator-(complex c){
            return {real-c.real,virt-c.virt};
        }
        complex operator*(complex c){
            return {real*c.real-(virt*c.virt),real*c.virt+virt*c.real};
        }
        void show(){
            if(real)
                std::cout<<real;
            std::cout<<(virt>0&&real?"+":"");
            if(virt){
                std::cout<<virt<<'i';
            }
            std::cout<<std::endl;
        }
        double module(){
            return sqrt(real*real+virt*virt);
        }
};
struct Complex{
    double real;
    double virt;
};
int main(){
    return 0;
}